Warped Disk Galaxies: Alignment with the Large-Scale Tidal Field

Abstract

A possible origin of disk galaxy warps is the misalignment between galactic disks and their host dark matter halos, the orientations of which are found to be statistically aligned with the large-scale tidal field. In this work, we test this scenario by examining the alignment between warped disk galaxies and the large-scale tidal field reconstructed from the ELUCID project. We find a statistically significant alignment signal between disk orientations and the $t_1$ direction, with warped and non-warped galaxies showing different alignment behaviors. Warped galaxies show an excess of intermediate angles and a preference for orientations slightly offset from perfect parallel and perpendicular alignments. In contrast, non-warped galaxies exhibit a deficit of intermediate angles relative to random expectations, which becomes more pronounced after matching to a control sample. We also find a clear mass dependence, with high-mass warped galaxies contributing the excess of intermediate-angle signal. No significant alignment signal in warped galaxies is detected with the $t_3$ direction.